Fix an issue that temp files are left permanently on storage after chrome crash

chrome/browser/download/download_history.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // DownloadHistory manages persisting DownloadItems to the history service by
 // observing a single DownloadManager and all its DownloadItems using an
 // AllDownloadItemNotifier.
 //
 // DownloadHistory decides whether and when to add items to, remove items from,
 // and update items in the database. DownloadHistory uses DownloadHistoryData to
@@ skipping 145 matching lines @@
           (previous->last_modified != current.last_modified) ||
           (previous->state != current.state) ||
           (previous->danger_type != current.danger_type) ||
           (previous->interrupt_reason != current.interrupt_reason) ||
           (previous->hash != current.hash) ||
           (previous->opened != current.opened) ||
           (previous->by_ext_id != current.by_ext_id) ||
           (previous->by_ext_name != current.by_ext_name));
 }
 
+bool ShouldCommitHistoryImmediately(const history::DownloadRow* previous,
+                                    const history::DownloadRow& current) {

[asanka, 2016/11/16 23:15:57]

Minor nit: You could fold this into ShouldUpdateHistory above. It can return a
3-state instead of a bool. I.e. NO, UPDATE, UPDATE_AND_COMMIT_IMMEDIATELY or
somesuch.

[qinmin, 2016/11/17 00:46:30]

Done.

+#if defined(OS_ANDROID)

[asanka, 2016/11/16 23:15:57]

Let's make this work on all platforms.

[qinmin, 2016/11/17 00:46:30]

Done.

+  // When download path is determined, Chrome should commit the history
+  // immediately. Otherwise the file will be left permanently on the external
+  // storage if Chrome crashes right away.
+  return (previous != nullptr) &&
+      (previous->current_path.empty() && !current.current_path.empty());
+#endif
+  return false;
+}
+
 typedef std::vector<history::DownloadRow> InfoVector;
 
 }  // anonymous namespace
 
 DownloadHistory::HistoryAdapter::HistoryAdapter(
     history::HistoryService* history)
     : history_(history) {
 }
 DownloadHistory::HistoryAdapter::~HistoryAdapter() {}
 
 void DownloadHistory::HistoryAdapter::QueryDownloads(
     const history::HistoryService::DownloadQueryCallback& callback) {
   history_->QueryDownloads(callback);
 }
 
 void DownloadHistory::HistoryAdapter::CreateDownload(
     const history::DownloadRow& info,
     const history::HistoryService::DownloadCreateCallback& callback) {
   history_->CreateDownload(info, callback);
 }
 
 void DownloadHistory::HistoryAdapter::UpdateDownload(
-    const history::DownloadRow& data) {
-  history_->UpdateDownload(data);
+    const history::DownloadRow& data, bool should_commit_immediately) {
+  history_->UpdateDownload(data, should_commit_immediately);
 }
 
 void DownloadHistory::HistoryAdapter::RemoveDownloads(
     const std::set<uint32_t>& ids) {
   history_->RemoveDownloads(ids);
 }
 
 DownloadHistory::Observer::Observer() {}
 DownloadHistory::Observer::~Observer() {}
 
@@ skipping 204 matching lines @@
   if (item->IsTemporary()) {
     OnDownloadRemoved(notifier_.GetManager(), item);
     return;
   }
 
   history::DownloadRow current_info(GetDownloadRow(item));
   bool should_update = ShouldUpdateHistory(data->info(), current_info);
   UMA_HISTOGRAM_ENUMERATION("Download.HistoryPropagatedUpdate",
                             should_update, 2);
   if (should_update) {
-    history_->UpdateDownload(current_info);
+    history_->UpdateDownload(
+        current_info,
+        ShouldCommitHistoryImmediately(data->info(), current_info));
     for (Observer& observer : observers_)
       observer.OnDownloadStored(item, current_info);
   }
   if (item->GetState() == content::DownloadItem::IN_PROGRESS) {
     data->set_info(current_info);
   } else {
     data->clear_info();
   }
 }
 
@@ skipping 38 matching lines @@
 }
 
 void DownloadHistory::RemoveDownloadsBatch() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   IdSet remove_ids;
   removing_ids_.swap(remove_ids);
   history_->RemoveDownloads(remove_ids);
   for (Observer& observer : observers_)
     observer.OnDownloadsRemoved(remove_ids);
 }